diff options
Diffstat (limited to 'src/backend/libpq/pqformat.c')
| -rw-r--r-- | src/backend/libpq/pqformat.c | 186 |
1 files changed, 181 insertions, 5 deletions
diff --git a/src/backend/libpq/pqformat.c b/src/backend/libpq/pqformat.c index 6f574e383b7..65fb49f48a5 100644 --- a/src/backend/libpq/pqformat.c +++ b/src/backend/libpq/pqformat.c @@ -15,10 +15,16 @@ * pq_getmessage, and then parsed and converted from that using the routines * in this module. * + * These same routines support reading and writing of external binary formats + * (typsend/typreceive routines). The conversion routines for individual + * data types are exactly the same, only initialization and completion + * are different. + * + * * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Header: /cvsroot/pgsql/src/backend/libpq/pqformat.c,v 1.29 2003/05/08 18:16:36 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/libpq/pqformat.c,v 1.30 2003/05/09 15:44:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -28,14 +34,20 @@ * pq_beginmessage - initialize StringInfo buffer * pq_sendbyte - append a raw byte to a StringInfo buffer * pq_sendint - append a binary integer to a StringInfo buffer + * pq_sendint64 - append a binary 8-byte int to a StringInfo buffer * pq_sendbytes - append raw data to a StringInfo buffer - * pq_sendcountedtext - append a text string (with character set conversion) + * pq_sendcountedtext - append a counted text string (with character set conversion) + * pq_sendtext - append a text string (with conversion) * pq_sendstring - append a null-terminated text string (with conversion) * pq_endmessage - send the completed message to the frontend * Note: it is also possible to append data to the StringInfo buffer using * the regular StringInfo routines, but this is discouraged since required * character set conversion may not occur. * + * typsend support (construct a bytea value containing external binary data): + * pq_begintypsend - initialize StringInfo buffer + * pq_endtypsend - return the completed string as a "bytea*" + * * Special-case message output: * pq_puttextmessage - generate a character set-converted message in one step * pq_putemptymessage - convenience routine for message with empty body @@ -43,8 +55,10 @@ * Message parsing after input: * pq_getmsgbyte - get a raw byte from a message buffer * pq_getmsgint - get a binary integer from a message buffer + * pq_getmsgint64 - get a binary 8-byte int from a message buffer * pq_getmsgbytes - get raw data from a message buffer * pq_copymsgbytes - copy raw data from a message buffer + * pq_getmsgtext - get a counted text string (with conversion) * pq_getmsgstring - get a null-terminated text string (with conversion) * pq_getmsgend - verify message fully consumed */ @@ -101,7 +115,7 @@ pq_sendbytes(StringInfo buf, const char *data, int datalen) } /* -------------------------------- - * pq_sendcountedtext - append a text string (with character set conversion) + * pq_sendcountedtext - append a counted text string (with character set conversion) * * The data sent to the frontend by this routine is a 4-byte count field * followed by the string. The count includes itself or not, as per the @@ -133,6 +147,34 @@ pq_sendcountedtext(StringInfo buf, const char *str, int slen, } /* -------------------------------- + * pq_sendtext - append a text string (with conversion) + * + * The passed text string need not be null-terminated, and the data sent + * to the frontend isn't either. Note that this is not actually useful + * for direct frontend transmissions, since there'd be no way for the + * frontend to determine the string length. But it is useful for binary + * format conversions. + * -------------------------------- + */ +void +pq_sendtext(StringInfo buf, const char *str, int slen) +{ + char *p; + + p = (char *) pg_server_to_client((unsigned char *) str, slen); + if (p != str) /* actual conversion has been done? */ + { + slen = strlen(p); + appendBinaryStringInfo(buf, p, slen); + pfree(p); + } + else + { + appendBinaryStringInfo(buf, str, slen); + } +} + +/* -------------------------------- * pq_sendstring - append a null-terminated text string (with conversion) * * NB: passed text string must be null-terminated, and so is the data @@ -152,9 +194,11 @@ pq_sendstring(StringInfo buf, const char *str) slen = strlen(p); appendBinaryStringInfo(buf, p, slen + 1); pfree(p); - return; } - appendBinaryStringInfo(buf, str, slen + 1); + else + { + appendBinaryStringInfo(buf, str, slen + 1); + } } /* -------------------------------- @@ -189,6 +233,35 @@ pq_sendint(StringInfo buf, int i, int b) } /* -------------------------------- + * pq_sendint64 - append a binary 8-byte int to a StringInfo buffer + * + * It is tempting to merge this with pq_sendint, but we'd have to make the + * argument int64 for all data widths --- that could be a big performance + * hit on machines where int64 isn't efficient. + * -------------------------------- + */ +void +pq_sendint64(StringInfo buf, int64 i) +{ + uint32 n32; + + /* High order half first, since we're doing MSB-first */ +#ifdef INT64_IS_BUSTED + /* don't try a right shift of 32 on a 32-bit word */ + n32 = (i < 0) ? -1 : 0; +#else + n32 = (uint32) (i >> 32); +#endif + n32 = htonl(n32); + appendBinaryStringInfo(buf, (char *) &n32, 4); + + /* Now the low order half */ + n32 = (uint32) i; + n32 = htonl(n32); + appendBinaryStringInfo(buf, (char *) &n32, 4); +} + +/* -------------------------------- * pq_endmessage - send the completed message to the frontend * * The data buffer is pfree()d, but if the StringInfo was allocated with @@ -205,6 +278,44 @@ pq_endmessage(StringInfo buf) buf->data = NULL; } + +/* -------------------------------- + * pq_begintypsend - initialize for constructing a bytea result + * -------------------------------- + */ +void +pq_begintypsend(StringInfo buf) +{ + initStringInfo(buf); + /* Reserve four bytes for the bytea length word */ + appendStringInfoCharMacro(buf, '\0'); + appendStringInfoCharMacro(buf, '\0'); + appendStringInfoCharMacro(buf, '\0'); + appendStringInfoCharMacro(buf, '\0'); +} + +/* -------------------------------- + * pq_endtypsend - finish constructing a bytea result + * + * The data buffer is returned as the palloc'd bytea value. (We expect + * that it will be suitably aligned for this because it has been palloc'd.) + * We assume the StringInfoData is just a local variable in the caller and + * need not be pfree'd. + * -------------------------------- + */ +bytea * +pq_endtypsend(StringInfo buf) +{ + bytea *result = (bytea *) buf->data; + + /* Insert correct length into bytea length word */ + Assert(buf->len >= VARHDRSZ); + VARATT_SIZEP(result) = buf->len; + + return result; +} + + /* -------------------------------- * pq_puttextmessage - generate a character set-converted message in one step * @@ -290,6 +401,38 @@ pq_getmsgint(StringInfo msg, int b) } /* -------------------------------- + * pq_getmsgint64 - get a binary 8-byte int from a message buffer + * + * It is tempting to merge this with pq_getmsgint, but we'd have to make the + * result int64 for all data widths --- that could be a big performance + * hit on machines where int64 isn't efficient. + * -------------------------------- + */ +int64 +pq_getmsgint64(StringInfo msg) +{ + int64 result; + uint32 h32; + uint32 l32; + + pq_copymsgbytes(msg, (char *) &h32, 4); + pq_copymsgbytes(msg, (char *) &l32, 4); + h32 = ntohl(h32); + l32 = ntohl(l32); + +#ifdef INT64_IS_BUSTED + /* just lose the high half */ + result = l32; +#else + result = h32; + result <<= 32; + result |= l32; +#endif + + return result; +} + +/* -------------------------------- * pq_getmsgbytes - get raw data from a message buffer * * Returns a pointer directly into the message buffer; note this @@ -324,6 +467,39 @@ pq_copymsgbytes(StringInfo msg, char *buf, int datalen) } /* -------------------------------- + * pq_getmsgtext - get a counted text string (with conversion) + * + * Always returns a pointer to a freshly palloc'd result. + * The result has a trailing null, *and* we return its strlen in *nbytes. + * -------------------------------- + */ +char * +pq_getmsgtext(StringInfo msg, int rawbytes, int *nbytes) +{ + char *str; + char *p; + + if (rawbytes < 0 || rawbytes > (msg->len - msg->cursor)) + elog(ERROR, "pq_getmsgtext: insufficient data left in message"); + str = &msg->data[msg->cursor]; + msg->cursor += rawbytes; + + p = (char *) pg_client_to_server((unsigned char *) str, rawbytes); + if (p != str) /* actual conversion has been done? */ + { + *nbytes = strlen(p); + } + else + { + p = (char *) palloc(rawbytes + 1); + memcpy(p, str, rawbytes); + p[rawbytes] = '\0'; + *nbytes = rawbytes; + } + return p; +} + +/* -------------------------------- * pq_getmsgstring - get a null-terminated text string (with conversion) * * May return a pointer directly into the message buffer, or a pointer |